Virgin Birth Produces Viable Shark Offspring
Image credit: Institute for Ocean Conservation Science
"The study shows for the first time that some virgin births can result in viable offspring."
This was one of those press releases that had me doing an immediate double take. Virgin births? Viable offspring? In fact, it announced the fact that virgin births in sharks even exist so matter-of-factly that it made me wonder if I just missed that class in biology. It turns out that virgin births are actually well documented in sharks. (Treehugger has also written about shark-administered c-sections, but that's another story...) In a process known as parthenogenesis, an egg or ovum fuses with a cell called a sister polar body, a byproduct of ova production, rather than with male sperm, to promote cell division. The sister polar body is nearly genetically identical to the ovum.
All this is, apparently, not news (although it was to me!), but what has scientists at the Institute for Ocean Conservation Science so excited is new research that proves virgin births can lead to long-lived, viable offspring:
"Genetic analysis led by a Field Museum scientist working with numerous colleagues has confirmed the first known case of a virgin female shark producing multiple offspring that survived. Two daughters of the white-spotted bamboo shark are now more than five years old. Earlier research proved that reproduction occurred in two other shark species without aid of male sperm, a phenomenon called parthenogenesis, but the offspring did not survive in those cases."
The study has important implications for conservation, with female sharks who found themselves stranded, for example, being able to still reproduce in the hope that one of her offspring would later find a mate. Douglas Sweet, one of the researchers, and now superintendent of the London State Fish Hatchery in London, suggested that we still have a lot to learn about this fascinating genus:
"Sharks have been around for hundreds of millions of years. I suspect they have some pretty interesting survival strategies that we are only now becoming aware of."
No word yet of any dolphins arriving with frankincense or myrrh, but you never know...